ENGINEERING.com has updated it's forum.  To post a question please visit the new Ask@ Forum.   

With a database of over 10000 questions the library will remain available for an extended period.
Q&A


fluidmechanics		 What happens what the stagnation pressure in creases to a thermally chocked supersonic flow with shock at exit View All
I have a converging-diverging nozzle connected to a constant area duct which is heated. The stagnation temperature and stagnation pressure before the nozzle is constant and the flow is supersonic inside the duct. The duct exit is chocked. What happens when everything stays constant but the stagnation pressure increases or decreases? Where does shock move?
12 years ago - 7 months left to answer. - 1 response - Report Abuse
Respond to question
    0      [lnkReport]        0       0       
Share |
  Responses

Niel
 If the stagnation pressure decreases below the critical value where the flow is chocked [1] the speed down stream of the orifice will no longer be super sonic and the shock waves will disappear.

If stagnation pressure is increased the initial shock will still be at the throat. With a properly designed C-D nozzle [2] you can get supersonic speeds, but the flow is still choke and the initial shock wave is at the same place.

Niel Leon
engineering.com

12 years ago

Source: [1] http://en.wikipedia.org/wiki/Choked_flow

[2] http://en.wikipedia.org/wiki/Convergent-divergent_nozzle


  0     0         

ENGINEERING.com does not provide engineering advice. The Ask@ service is a forum for members to exchange ideas relating to the world of engineering. We caution users not to accept any responses that they receive without further validation, and not to rely on any engineering advice that they may get from other members of the Ask@ forum. ENGINEERING.com specifically disclaims any obligation to validate or verify any information posted within the Ask@ service. ENGINEERING.com encourages users to seek the services of a professional engineer for any engineering advice they may require.